Past IABSE Webinars
IABSE Webinar: Resilience-Based Management of Bridge Portfolios in Seismic Regions

Date: 9 July (Friday), 2021, 14-15 hrs (CET).

Recorded Video: Click Here

 

After registering you shall receive the Zoom meeting link, before the webinar.

 

Speaker: Prof. Anastasios Sextos, PhD, MASCE, FHEA, Professor of Earthquake Engineering, Head of Earthquake and Geotechnical Engineering Research Group, University of Bristol, UK.

 

Roadway infrastructure (primarily bridges, overpasses and junctions) form an interconnected and complex system of assets that is designed to facilitate the continuous provision of services essential to the functioning of society, especially in highly urbanized regions. Resilience of this system, namely its ability to withstand, adapt to, and rapidly recover after a disruptive event, is therefore vital for the safety, security and prosperity of our communities. This presentation focuses on two of the most important challenges towards holistic disaster risk mitigation and management: (a) quantification of roadway infrastructure resilience in a way that is meaningful and applicable for informed decision-making and (b) rigorous, yet computationally efficient, assessment of superstructure and its supporting subsoil as a holistic, dynamic and interacting system. The outcomes of several research projects will be critically reviewed focusing on the reliable consideration of epistemic and aleatoric uncertainties propagating from the hazard to the structural component level, the structure and the network level. RETIS-Risk is such a multi-disciplinary project that considers the above aspects of highway network resilience to seismic loading and establishes a comprehensive, multi-criterion framework for mitigating the overall loss experienced by the community after an earthquake event. Vulnerability of bridges and overpasses is assessed in detail considering dynamic soil-structure interaction (SSI) effects. Loss is decoupled into direct (i.e., arising from structural/geotechnical damage) and indirect, associated with the travel delays of the network users, as well as the wider socio-economic consequences in the affected area. Given the computational demand for large scale finite element modelling associated with dynamic SSI problems, recent advances in reduced order modelling will be presented next. This work relates to multi-objective optimization of Lumped Parameter Models (LMP) and permits consideration of frequency- and intensity-dependent SSI in the time domain. The talk will further present an application of the above computational scheme for the case of a large highway network in Greece and conclude with a spectrum of ideas for future research in the field of structural, earthquake and resilience engineering.

 

 

IABSE Webinar: Risk Management of Large Scale Projects

Date: 24 June, 2021, 13-14 hrs (CET).

 

Recorded video: https://iabse-elearning.org/lecture-series.html

 

Extreme events are usually far away in our minds. If they occur, nevertheless, they often hit us unexpectedly. When single events with severe consequences for the environment and people occur, most people perceive them as extreme.

On the other hand, anyone hardly cares about a large number of smaller events over a longer period of time, whose combined impact is of similar magnitude.

Particularly in large construction projects, the occurrence of unexpected, extreme events, such as natural hazards, could result to e.g. the collapse of a bridge or a fire in a tunnel quite often and this causes a shock effect, also perceived by the public. Moreover, the overrun of costs and construction time, caused by unknown risks, could lead to fear and blame. In this presentation, Konrad Bergmeister shows a possible way on how such unknown risks, but also unknown opportunities can be countered. Based on scientific principles and extensive practical experience, he addresses a structured holistic opportunity-risk management for large projects. In his Life-Talk, the issue of the Corona Pandemic is also addressed from the perspective of risk-reward management.

 

Speaker: Konrad Bergmeister, Univ.-Prof. Dipl.-Ing. M. Sc. Ph. D. Dr. phil. Dr. techn. DDr.-Ing. e.h. Konrad Bergmeister is head of the Institute of Structural Engineering at the University of Natural Resources and Applied Life Sciences, in Vienna, Austria. He is editor of the Beton-Kalender and the journal Beton- und Stahlbetonbau. Until 2019, he was responsible for the planning and construction of the Brenner Base Tunnel, and before that he was chief engineer of the Brenner Motorway. Now, he is working again as a civil engineer, with the Bergmeister engineering office being active with competence in all classical engineering disciplines and in four different locations Brixen (IT), Munich (DE), Vienna (AT) and Zurich (CH).

 


IABSE Webinar: Concrete Plasticity – A Historical Perspective

Date: 10 June (Thursday), 2021, 14-15 hrs (CET).

 

Recorded video: https://iabse-elearning.org/lecture-series.html

 

This webinar is being organised by the Danish Group of IABSE. The presentation shall review the development of limit analysis, from Galileo through Coulomb to the Mathematical Theory of Plasticity formulated by Hill and Hodge, Prager & Drucker and independently by Gvozdev. The application to structural concrete slabs was pioneered by Johansen and Gvozdev, and extended to walls (membranes), beam shear and punching shear by Nielsen and the Copenhagen Shear Group. Simultaneous and subsequent advances were – and are - made by research groups in a.o. Zurich, Cambridge, Toronto, Houston and Lausanne. The concept of yield lines, essential for the development of solutions, is introduced, and the distinction from the conventional notion of cracks shall be discussed. An overview of applications will be given, focusing on slab flexure, in-plane and beam shear, and punching shear.

 

Speaker: Mikael W. Braestrup obtained his Ph.D. in structural engineering from the Technical University of Denmark in 1970, and subsequently spent two years as a volunteer in charge of low-cost road construction in the Peruvian Andes. Prior to joining the consulting company Ramboll in 1979 Dr Braestrup was engaged in research and teaching in Copenhagen, Denmark, and Cambridge, U.K., principally working on the application of classical plasticity theory to structural concrete members subjected to shear. During the period 1992 - 2005, he worked in the Ramboll Department of Bridges, a major assignment being the preparation of the design basis, with the application of Eurocodes, to the 16 km Øresund Link road and rail strait crossing between Denmark and Sweden. Since 2005 he is attached to the Ramboll Energy division, department of Pipelines, on a part-time basis since 2015. Dr Braestrup has been an active member of IABSE since 1979, when he co-organised the Copenhagen Colloquium on ‘Plasticity in Reinforced Concrete’ and received the IABSE Prize in 1984, and went on to serve in several organising and editorial boards.

 

Moderator: Tina Vejrum, is the Chair of IABSE’s Danish National Group, Vice President of IABSE, and Vice President of the Major Bridges International Dept. At COWI, in Denmark. Her special competences include extensive line management and project management. She has been extensively engaged with IABSE in various committees and is also member of the SEI Editorial Board.

 


IABSE Webinar: The Chirajara Bridge Collapse

Date: 27 May (Thursday), 2021, 14-15 hrs (CET).

 

Recorded video: https://iabse-elearning.org/lecture-series.html

 

On January 15, 2018 at 11:49, the west pylon B of the Chirajara Bridge, with its cantilevered cable-stayed superstructure, collapsed during construction of final parts of the bridge girder – just before closure at midspan. The crossing is located approximately 20km NW of Villavicencio, Colombia. The collapse led to the immediate and total destruction within seconds of the Pylon, together with the erected span of the bridge girder. Authorities reported nine fatalities resulting from the collapse. Shortly thereafter, the project insurer QBE Segures, Colombia commissioned an independent investigation into the collapse of the bridge, through loss adjusters ONC Adjusters, Bogotá, Colombia. An international team of bridge engineering experts was assembled to undertake the investigation. The investigation was completed in August, 2018. The causes of the failure and the sequence of successive and progressive failures of the individual structural components and thus the entire mechanism of the bridge collapse was identified and analyzed. Key findings and recommendations from the investigation, as well as lessons that may be extracted from this unfortunate event, will be presented.

 

Presenters:

Christos T. Georgakis is Professor of Structural Dynamics and Monitoring at Aarhus University, a position he formerly held at the Technical University of Denmark. Having worked briefly at the engineering consultancies Flint & Neill Partnership in London and later at Force Technology in Copenhagen, he went on to establish the specialist engineering consultancy Georgakis & Associates. His consultancy engagements have included Hong Kong’s Stonecutters Bridge, Scotland’s Queensferry Crossing, the Gordie Howe International Bridge and the Port Mann Bridge in Canada. His research focuses on structural dynamics, aerodynamics and vibration control, with several patented technologies in the fields of wind turbine vibration control and bridge cables ascribed to him. He is co-author of the well-known book Cable Supported Bridges, Concept and Design and he is an IABSE Fellow. On behalf of the bridge insurers, Professor Georgakis was tasked with assembling an international team of experts and leading the overall investigation of the cable-stayed Chirajara Bridge collapse in 2018.

 

Klaus H. Ostenfeld is honorary Professor in Bridge and Structural engineering at Aarhus University, and former President CEO for COWI, Consulting Engineers. He graduated 1966 with a M.Sc. degree from Danish Technical University. He majored in design of major bridges and has spent most of his 55-year carrier in the field of major bridge design and construction internationally. After a few years in a Danish consulting firm Klaus was employed by an American consultant in St Louis, MO. and Phoenix AZ. where he obtained his registration as Professional Engineer and after 3 years, he became employed in Paris in the French firm Europe Etudes for 4 years where he became project responsible for the design and construction of the advanced posttensioned shell structures for the Olympic Games in Montreal, Canada 1976. Since 1977 Klaus was engaged in the design of the huge Great Belt Project comprising the world record suspension span of 1.624 m and other world record bridges like the Normandy bridge steel superstructure in France and the Oresund Link before he became Group CEO for the COWI Group which he developed from 2000 to 5000 employees before his retirement. Klaus Is now honorary professor at Aarhus University and recognized international expert consultant with assignments in several countries. Klaus served as president for IABSE 1997-2001 and Chair of the IABSEFoundation 2004-2011 and is Honorary member and Fellow of IABSE as well as many other professional organizations including ASCE and VDI. Klaus has received numerous international awards and prizes. As professor Klaus has taken particular interest in educating in structural understanding and behavior including the analysis of the catastrophic failure of the Chirajara Bridge.

 

Webinar: Ultra-High-Performance-Concrete (UHPC)

Date: 30 April (Friday), 2021, 14-15 hrs (CET, GMT +1).

Speaker: Prof. Lukas Vrablik, Czech Republic; Moderator: Prof. Roman Lenner, South Africa.

Organised by the South African Group of IABSE.

 

Recorded video: https://iabse-elearning.org/lecture-series.html

 

The topic of webinar will be practical use of Ultra-High-Performance-Concrete (UHPC) as the main material for superstructure of pedestrian bridges. Two practical examples of real pedestrian bridges will be presented – first is a segmental single span bridge (completely made by UHPC segments) and the second example is a cable stayed pedestrian bridge where the superstructure is composed of UHPC segments. Information about design (material and structural analysis, detailing and construction stages) will be described and presented.   

 

Moderator: Roman Lenner – Associate Professor at Stellenbosch University and IABSE National Chair of South Africa, Member of IABSE TG1.3 Work Group and Joint Committee for Structural Safety. Main research interests are structural reliability, bridge design and bridge traffic loading. Practical experience involves bridge design in USA and design review of tunnels in Germany along with working as a World Bank consultant for transportation projects in southern Africa.

 

Speaker: Lukas Vrablik – Associated professor CTU in Prague, Head of Department of Concrete and Masonry Structures; Technical director Valbek; Member of group for Eurocode and Model Code implementation; specialized for bridge design (long span bridges, arch bridges, pedestrian bridges), mathematical simulations of structure and material behaviour; monitoring of existing structures. Author or co-author of more than 100 publications and contributions to proceedings, 2 patents, 1 momograph.


Webinar: ​Parametric Structural Design with Isogeometric Analysis

Date: 9 April (Friday), 2021, 14-15 hrs (CET, GMT +1).

Speaker: Dr. Anna Bauer, Germany; Moderator: Prof. Jan Wium.

Organised by the South African group of IABSE.

 

Recorded video: https://iabse-elearning.org/lecture-series.html

 

Isogeometric analysis (IGA) is a fairly new approach within finite element analysis. In contrast to classical approaches that require a replacement of the CAD model by a finite element model, IGA omits this step by using the same parametric description also for the analysis. The Ansatz functions used are usually Non-uniform Rational B-Splines (NURBS). The smooth basis functions and the seamless link to CAD provides a lot of possibilities in the design of structures. This talk will give a brief overview of IGA and the respective requirements and challenges. Furthermore, the potentials of the method within the parametric design of light-weight structures, such as bending-active structures with mounting processes and form finding of tensile membrane structures, are highlighted.

 

Speaker: Dr. Anna Bauer is a structural engineer at Mayr Ludescher Partner and recently finished her Ph.D. at the Chair of Structural Analysis of Prof. Dr.-Ing. K.-U. Bletzinger at the Technical University of Munich. She is exploring and developing the novel simulation approach of isogeometric analysis with CAD-integration for the design of lightweight structures. The applications are manifold but one main focus is the construction process of bending-active structures. She received her B.Sc. (2012) and M.Sc. (2015) in Civil Engineering at the Technical University of Munich. In 2018, she was awarded the IASS Hangai Prize for her paper on sliding cables with isogeometric analysis at the annual symposium.

 

Moderator: Prof. Jan Wium, responsible for the discipline in Construction Engineering and Management, at Stellenbosch Univeristy, South Africa. His research areas encompass construction risk, design management, modular construction and the use of technology in construction. He has served as an Editorial Board Member for IABSE's journal SEI, and as a governing body member in several committees within IABSE. He completed his PhD from EPFL, Lausanne, Switzerland.

 


Risk-based asset management and the potential of UHFB in railway bridge construction from the point of view of the infrastructure operator

 

Web meeting March 4th, 2021. 16: 00-17: 00. Speaker: Dipl.-Ing. Herbert Friedl, SBB AG - infrastructure, Head of Asset Management in Civil Engineering.

 

Language: German. Organised by Austrian Group of IABSE. 

 

Recorded video: https://iabse-elearning.org/lecture-series.html

  

The Swiss Federal Railways -SBB- manage a remarkable infrastructure system with over 6,000 bridges, more than 17,000 retaining walls and over 400 tunnels. These structures alone represent a replacement value of around 30 billion Swiss francs. So far, decisions regarding building maintenance and future cost planning have mainly been used for the condition classes (grades) of the individual buildings.

 

As part of the further development of the asset management of civil engineering structures, a change from the condition-based approach to a risk-based approach is planned. Many additional parameters are taken into account. Evaluations of the probability of failure of structures, estimates of the volume of traffic on the lines and on the bridges, etc.

 

A risk-based model for railway bridges has been developed and can be used to identify top risks and differentiate at the network level. In 2017, the SBB realized a railway bridge which was built from reinforced UHFB.

 

The advantages of structures made of UHFB are lower life cycle costs and, thanks to the modular design with a high degree of prefabrication, enable shorter construction times and thus fewer operational restrictions. The bridge with a span of 6.0 m was equipped with a monitoring system in order to record the behavior of the structure as a result of train crossings. After three years of monitoring, the results confirm the correct behavior of the bridge and future structural maintenance will be carried out according to existing standards. This webinar will introduce the new risk-based approach to asset management and presents UHFB applications at SBB.

 

 
Webinar: Structural Analysis & Design Using Advanced Software: A Six-Story Building Application

February 22, 2021 Organised by the Philippine group of IABSE.

 

 
IABSE Webinar: "Incremental Launching - Multispan Steel Bridges”

 

Moderator: Rafael Martinez (Spain), Speaker: Javier Martinez (Spain).

Date: 4 February, 2021, 14-15 hrs (CET).

Recorded video: https://iabse-elearning.org/lecture-series.html

 

Description: This webinar is an initiative by IABSE Task Group 4.14 (Commission 4) on Special Heavy Lifting Equipment, Chaired by Javier Martinez. This online presentation and Q&A session will review the different technologies and specific tools developed during the last few years for incremental launching multispan bridges showing different types of soiutions, depending on the geometry of the deck, and even regions. 

 

About the Speaker: Javier Martinez, born in Madrid, Spain, graduated as Naval Architect at the Polytechnic University of Madrid, and thereafter his interest was focused in the transport and installation of oversized pieces, as in offshore as in onshore sectors. In 1983, he founded the company LASTRA in Spain. LASTRA specialized in the engineering and final installation of heavy equipment which couldn’t be installed by a crane. He was involved in the design of new tools and concepts of skidding and lifting.  Around the end of the 80’s, vital civil projects were performed in the European Community, which gave rise to the Universal Exhibition at Sevilla, and the Olympic Games in Barcelona. LASTRA designed and implemented innovative solutions, transferring such knowledge and experience to other countries. In 1991, LASTRA was sold to the Australian Industrial Group BRAMBLES and later on to UK ALE. Both companies gave the financial support needed to continue with the development and new designs. In January 2020 ALE was sold to MAMMOET where J. Martinez is the Global Commercial Director.

 

About the Moderator: Rafael Martinez was born in Madrid in 1979. He graduated as BEng in Civil Engineering by the Universidad Politecnica de Madrid in 2004. His whole career has been related to the civil engineering business, starting in with Spanish civil contractor Acciona. In 2007 he joined former ALE Lastra, guiding his professional activities to the applications of heavylifting for civil projects, and showing from the beginning a particular interest in bridge construction by heavlifting methodologies. He was Project Engineer at ALE Lastra during 4 years and was involved in landmark projects such as the Bridge Pavilion in Zaragoza by Zaha Hadid, and many other bridge launching jobs, among other heavylifting projects. Later on and still with ALE Lastra, he oriented his career into a commercial role focused on the civil market. In 2014 he joined Mammoet, being first Account Manager and afterwards and for the last couple of years, Manager of the Spanish Branch. In 2020, after the acquisition of ALE by Mammoet, Rafael met up again with his former ALE Lastra colleagues where developed many of his skills in civil heavylifting. Currently he is responsible for civil market commercial activities within Mammoet.

 


 

IABSE Discussion: Pure tension! Two bridges in the heart of the new A5 motorway north of Vienna

 

Speaker: DI Dr. Michael Kleiser, ASFINAG Baumanagement GmbH

Date: 17 December 2020, 14-15.00 Hrs CET

Organised by: IABSE Austrian Group.

 

Abstract: At the end of 2017, ASFINAG erected two new bridges in the immediate vicinity of the north part of Vienna, which generated tension in different ways. The “Satzengrabenbrücke” is designed as an integral structure and contains new, maintenance-free roadway crossings, consisting of precast concrete elements placed next to one another that distributes the temperature-related displacements evenly over the asphalt above. This way, the stresses in the asphalt are limited to a tolerable level so that it remains free of cracks. Furthermore, the overpass bridge “A5.Ü20”, as an inclined post construction, triggers tension in the psychological sense of perception. A dynamic play of shapes with inclines and curvatures, which visually underpin the force transfer of the bridge, increases the overall expression and, thus, sets an accent in the middle of the new A5 north / Weinviertel motorway.

 

Spannung Pur! - Zwei Brücken im Herz der neuen A5 nördlich von Wien

DI Dr. Michael Kleiser, ASFINAG Baumanagement GmbH

 

Kurzfassung: Die ASFINAG errichtete Ende 2017 zwei neue Brücken in unmittelbarer Nachbarschaft im Norden Wiens, die in unterschiedlicher Weise Spannungen erzeugen. Die als integrales Tragwerk konzipierte Satzengrabenbrücke beinhaltet neuartige, wartungsfreie Fahrbahnübergänge, die die temperaturbedingten Verschiebungen durch aneinander gereihte Betonfertigteile gleichmäßig auf den darüber liegenden Asphalt verteilen. Dadurch werden die Spannungen im Asphalt auf ein erträgliches Maß begrenzt, sodass dieser rissefrei bleibt. Des Weiteren löst die Überführungsbrücke A5.Ü20 als Schrägstielkonstruktion Spannung im wahrnehmungspsychologischen Sinn aus. Durch ein dynamisches Formspiel mit Schrägen und Krümmungen, die die Kraftabtragung der Brücke visuell untermauern, wird der Gesamtausdruck gesteigert und somit ein Akzent in der Mitte der Neubaustrecke A5 Nord/Weinviertler Autobahn gesetzt.